Commonly Asked Questions Thermoplastic Enclosure or Polycarbonate Enclosures

    • Each enclosure is shipped assembled with the base, cover with the gasket installed with four threaded inserts on the back of the base, four for cover attachment, and four for back panel attachment. Also included is a packet with four mounting feet and four mounting feet screws.

    • Yes. All our polycarbonate enclosures are NEMA 4X. As opposed to many competitors’ products, our enclosures are 4X with latches only or with two screws (in the case of a hinged cover). NEMA 6P enclosures are also available.

    • Standard color is gloss gray for the Polycarbonate Enclosure line. Custom molded color is available.

    • Our Polycarbonate enclosures are listed as UL-50E, Cabinet and Cutout Boxes. Our file number is E207562. The enclosure is also C-UL Listed for use in Canada and we are Marine Listed for coastal or marine applications.

    • The covers and sidewalls of all the enclosures are slightly convex. This was done to ensure that the covers and the base will resist warping, which is a problem that plagues non-metallic “flat” enclosures. A warped cover or base will not seal properly, and water tightness fails as a result. Another benefit of the shaping is to provide a stronger box. Therefore, standard hubs and components can be installed and seated on the surfaces of the enclosure, using standard gaskets.

    • Yes, modifications such as machined holes or slots are available. We can also provide latch installation, DIN-rail installation, or back panel installation. Contact us for more information and a quote. Also, we do have CAD drawings downloadable from our website. Use those to define the shape and location of your modifications and e-mail them to us at

    • Yes, we offer back panels in coated steel, bare aluminum and PVC

    • Probably not. All polycarbonate enclosures feature molded-in mounting bosses on the bottom of the enclosure at intervals of approximately 1 inch, located around the entire perimeter of the enclosure. This allows you to install DIN rails at virtually any location, avoiding the need and expense of a back panel.

    • The Back Panel Adjustment System consists of four mounting pads that slide on T-shaped rails molded into the four corners of the enclosure base. The mounting pages, which are provided with brass threaded inserts for panel attachment, are held in place by inserting a set screw. The set screw, which can be adjusted with the back panel in place, is inserted into a channel in the mounting pad, which causes the set screw to engage with the T-rail, providing a positive attachment. The kit includes four mounting pads, eight set screws, an Allen wrench, four back panel attachment screws, and an instruction sheet (PN’s BPAKG and BPAKB).

    • You can order clear covers, with gaskets installed, and easily replace it in the field.

    • There are several important advantages:

      1. The engineered thermoplastic enclosure has dramatically better impact resistance. For example, our enclosure has an impact resistance of over 900 in-lbs, while fiberglass typically has an impact resistance of less than 220 in-lbs.
      2. Thermoplastic enclosures are available with a clear cover. For a fiberglass product, an expensive and potentially leaky window installation is required.
      3. Thermoplastic enclosures feature a 100% non-metallic hinge design. Fiberglass products normally feature a steel hinge pin that will eventually corrode.
      4. Thermoplastic enclosures tend to offer more features inside the enclosure to support component installation. For example, fiberglass products tend to have only four mounting bosses on the base of the box. The products Sealcon offers feature those same four mounting bosses, plus molded-in mounting bosses surrounding the perimeter of the enclosure (see the DIN-rail comment above). We also offer the patented Back Panel Adjustment System, which eliminates the need for expensive stand-offs or allows the installation of multiple panels.
      5. Thermoplastic enclosures are much easier and safer to machine, with none of the dust and splintering associated with fiberglass.
      6. Fiberglass enclosures will “bloom” when exposed to sunlight. In fact, manufacturers of FRP enclosures recommend painting their products. This is not necessary with the thermoplastic enclosures we provide.
    • Sealcon provides “dual-dimension” data for our line of enclosures. Also, note that the “DIN rail friendly” design speaks directly to the need for European-designed components and the spreading use of DIN rail mounted components.

    • Screw-closed configurations, including the hinged versions as well as the non-hinged versions, are now UL-Type 6P rated when the four provided attachment screws are used. The enclosures with integrated latches are 6P rated as well.

    • Chemical – Chemical thread locking compounds are not recommended. Anti-seize thread release agents are also not recommended. Mechanical – A mechanical thread locking device is acceptable, such as a lock washer, provided a flat washer is used between the locking element and polycarbonate.

    • Mounting Feet/Flange – 25-30 in-lbs.
      Back Panel – 10-15 in-lbs.
      Enclosure Cover – 8-10 in-lbs.

    • Only light soapy water is recommended to clean your polycarbonate enclosure.